The invention relates to reciprocating piston machines, such as fluid pressure engines, compressors, and pumps, and, more particularly, to an eccentric-cam type transmission mechanism for connecting the reciprocating piston of an internal combustion engine to a rotating drive shaft such that the piston moves in true straightline fashion along the longitudinal axis of the cylinder.
Conventional crankshaft drive transmissions for the reciprocating piston of a fluid pressure machine, such as an internal combustion engine, have connecting rod angularity relative to the longitudinal axis of the piston cylinder in moving the piston back and forth within the cylinder. This angled force acting on the piston causes the piston to experience sidewall pressure due to piston engagement of the cylinder wall, which sidewall pressure leads to destruction of the cylinder wall oil film and creates a rubbing friction retarding movement of the piston. This rubbing action on the piston reduces the ultimate compression ratio and leads to a decrease in horsepower efficiency.
It is further typical for the drive transmission of a reciprocating piston engine to utilize a single crankshaft throw per piston, thus limiting the ultimately achievable compression ratio to that which can be safely carried by the single crankshaft.
The present invention offers a transmission mechanism for a reciprocating piston which eliminates connecting rod angularity and permits higher compression to be obtained, which translates into better efficiency and greater horsepower, in the case of an internal combustion engine. The present invention also provides for a simplified arrangement for separately removing a piston from a cylinder, such as to replace piston seal rings, which arrangement is permitted by virtue of the straightline motion of the piston in the cylinder.